For example, as a related art flow rate-controlling valve applied to the flow rate control of the cooling water of the vehicle, for example, a flow rate-controlling valve disclosed in following Patent Document 1 has been known.
That is, this flow rate-controlling valve has a cylindrical housing in which a first discharge port that is connected to a radiator, a second discharge port that is connected to a heat exchanger for a heater and a third discharge port that is connected to an oil cooler are arranged parallel along an axial direction, and a cylindrical valve body that is rotatably supported in the housing and has first to third opening portions whose overlap states with the respective discharge ports are changed according to a rotation position (phase) of the valve body. This flow rate-controlling valve controls a distribution destination and the flow rate of cooling water by the fact that the rotation position of the valve body is controlled according to a vehicle operating condition by an electric motor.